Suchergebnisse

6 Figuras.- 3 Tablas ; Synthetic fuel production from renewable energy sources like biomass is gaining importance driven by the ambitious targets for reducing greenhouse gas emissions worldwide. Sorption enhanced gasification (SEG) proposes carrying out the gasification of biomass in the presence of a CO2 sorbent, which allows producing a syngas with a suitable composition for a subsequent synthetic fuel production step. This study aims at analysing the effect of different operating parameters (e.g. steam-to-carbon (S/C) ratio, CO2 sorption capacity and sorbent-to-biomass ratio) in the syngas composition and char conversion obtained in a 30 kWth bubbling fluidized bed gasifier, using grape seeds as feedstock. The importance of reducing the formation of higher hydrocarbons through a high steam-to-carbon ratio and using a CO2 sorbent with high sorption capacity is assessed. C3-C4 and unsaturated C2 hydrocarbons contents below 1%vol. (in dry and N2 free basis) can be achieved when working with S/C ratios of 1.5 at gasification temperatures from 700 to 740 °C. Varying the amount of the CO2 separated in the gasifier (by modifying the temperature or the CO2 sorption capacity of the sorbent) the content of H2, CO and CO2 in the syngas produced can be greatly modified, resulting in a module M = (H2-CO2)/(CO + CO2) that ranges from 1.2 to almost 3. ; This work has been carried out as part of the European Commission Horizon 2020 Framework Programme project FLEDGED (Grant agreement No. 727600) and the project WASYNG (No. RTI2018-095575-B-I00) funded by the Spanish Ministry of Science, Innovation and Universities. Authors thank also the Regional Aragon Government (DGA) for the economic support under the research groups' support programme. ; Peer reviewed

13 Figuras.- 2 Tablas ; In this work, the feasibility of an entrained flow reactor for full decarbonisation of gas streams has been proved. Three CaO-based materials (two types of lime and calcined raw meal) with different textural properties and therefore, different CO2 carrying capacities have been fed to the entrained flow reactor in a series of tests in which the Ca/CO2 molar ratio and solid residence time were the operation variables studied. Up to 11 mol CO2 m−2 s−1 has been captured from the gas phase with CaO from calcined lime with a maximum CO2 carrying capacity of 0.57 mol CO2 per mol CaO, reaching CO2 capture efficiencies over 90% for a Ca/CO2 molar ratio of 5 and solid residence times under 5 s. ; This work acknowledges the support from the Spanish Ministry of Economy, Industry and Competitiveness through the funding of the project ENE2015-68885-C2-2-R. The authors are also grateful for support from the Regional Aragon Government (DGA) under the research groups' support program. ; We also acknowledge institutional support from the Unit of Information Resources for Research at the "Consejo Superior de Investigaciones Científicas" (CSIC) for the article-processing charges contribution ; Peer reviewed

Functional materials for the sorption enhanced reforming process for H2 production coupled to a Cu/CuO chemical loop have been synthesized. The performance of CuObased materials supported on Al2O3, MgAl2O4 and ZrO2 and synthesized by different routes has been analyzed. Highly stable materials supported on Al2O3 or MgAl2O4 synthesized by co-precipitation and mechanical mixing with sufficient Cu loads (around 65 %wt.) have been successfully developed. However, it has been found that coprecipitation under these conditions is not a suitable route for ZrO2. Spray-drying and deposition precipitation did not provide the best chemical features to the materials. As the Ca/Cu process is operated in fixed bed reactors, the best candidates were pelletized and their stability was again assessed. Pellets with high chemical and mechanical stability, high oxygen transport capacity and good mechanical properties have been finally obtained by co-precipitation. The good homogeneity that provides this route would allow an easy scaling up. ; This work acknowledges the support by European Union Seventh Frame Programme FP7 under grant agreement n° 608512 (ASCENT Project). Laura Díez acknowledges the FPI fellowship (ENE 2012-37936-CO2-01, BES-2013-064616 financed by MINECO). ; Peer reviewed

Sorption Enhanced Reforming (SER) is a very promising option that allows H2 production coupled with capturing CO2 by sorption. The present research work focus in the sorbent point of view and several synthetic materials with a high CO2 absorption capacity and chemically and mechanically stable during multi-cyclic operation (at least 40 calcination-carbonation cycles and 100 cycles in some cases) under the typical SER process conditions have been developed. Two different synthesis routes (co-precipitation and mechanical mixing) have been followed trying to evaluate the effect of two different inert supports (magnesium oxide and mayenite) on the evolution of the CO2 carrying capacity of the materials. Also, sorbents have been synthesized with different morphologies (powder and particles) and sizes (from 100 microns up to 2 mm) in order to test their reactivity and mechanical suitability for large scale reactor system operation. Synthetic dolomite with a molar CaO/MgO ratio of 2:1 synthesized by co-precipitation method exhibited very stable performance for 100 consecutive carbonation/calcination cycles and a residual CO2 carrying capacity of 0.29 grCO2/grcalcined sorbent. Also a very promising result has been obtained for this sorbent mixed with a commercial catalyst in a preliminary SER experiment that yield a H2 production of 92 % vol. (d.b.). ; The authors acknowledge support from the European Union Seventh Framework Programme FP7 under grant agreement nº 608512 (ASCENT Project) and the Regional Aragon Government (DGA) under the research groups support program (Consolidated group DGA-T11). ; Peer reviewed

5 figures, 5 tables.-- Supplementary information available. ; Gasification represents a potential technology for the conversion of biomass into usable energy. The influence of the main gasification parameters, i.e. the type of biomass used and its composition, as well as the composition of the outlet gas, were studied by a multivariate statistical analysis based on principal component analysis (PCA) and partial least square (PLS) regression models in order to identify the main correlations between them and to the contents of methane, ethylene and tar in the outlet gas. In this work, the experimental data used as input for the multivariate statistical analysis came from a TRL-4 gasification plant running under sorption enhanced conditions, i.e. using steam as the gasifying agent and CaO as the bed material. The composition of the biomass feed played an important role in the quality of the outlet gas composition. In fact, biomasses with high ash and sulphur contents (municipal solid waste) increased ethylene content, while those with high-volatile matter content and fixed C content (wood pellets, straw pellets and grape seeds) mainly increased CO and CO2 formation. By increasing the gasification bed temperature and the CaO/C ratio, it was possible to reduce the methane and the collected tar contents in the outlet gas. Other light hydrocarbons could also be reduced by controlling the Treactor and TFB. Methane, ethylene and tar contents were modelled, cross-validated and tested with a new set of samples by PLS obtaining results with an average overall error between 8 and 26%. The statistically significant variables to predict methane and ethylene content were positively associated to the thermal input and negatively to the CaO/C ratio. The biomass composition was also remarkable for both variables, as mentioned in the PCA analysis. As far as the tar content, which is undesirable in all gasification processes, the decrease in the tar content was favoured by high bed temperature, low thermal input and biomass with high-volatile matter content. In order to produce an outlet gas with adequate quality (e.g. low tar content), a compromise should be found to balance average bed temperature, sorbent-to-mass ratio, and ultimate and proximate analyses of the biomass feed. ; This work was supported by the Spanish Ministry of Science and Innovation, the State Research Agency and the European Funds for Regional Development (No. RTI2018-095575-B-I00, MCI/AEI/FEDER, UE) and the Regional Aragon Government (DGA) under the research groups' support programme and the research project LMP178_18. I. Martínez thanks the grant RYC2019-026929-I funded by MCIN/AEI/10.13039/501100011033 and EI FSE Invierte en tu futuro. ; Peer reviewed

Abstract of the talk delivered at the 29th European Biomass Conference and Exhibition, EUBCE 2021, Virtual, Online, 26 April 2021 - 29 April 2021 ; In this work, a sorption-enhanced gasification (SEG) process is studied using the organic fraction of a Municipal Solid Waste (MSW) as feedstock in a 30 kWth bubbling fluidised bed (BFB) reactor. Experiments using steam-to-carbon ratios in the range of 1 to 1.5 molH2O/molC with different sorbent-to-biomass proportions and gasification temperatures were conducted in a 30 kWth bubbling fluidized bed reactor. Solid residence time in the reactor was modified through the biomass and CO2 sorbent flow rates fed to the reactor. The influence of each operating variable in the syngas composition as well as in the yield and composition of the tar produced has been determined through these experiments. Moreover, it has been calculated char conversion in the gasifier for the different experiments performed with the objective of elucidating a semi empirical model for predicting such conversion as a function of the gasification temperature and solid residence time in the reactor. ; This work has been supported by the European Commission (FLEDGED project, grant agreement No. 727600); the Spanish Ministry of Science and Innovation, the State Research Agency and the European Founds for Regional Development (No. RTI2018-095575-B-I00, MCI/AEI/FEDER, UE); and the Regional Aragon Government (DGA). ; Peer reviewed

5 figures, 1 table ; Syngas production via steam gasification is one of the thermochemical processes with the greatest potential for obtaining synthetic fuels from a solid fuel, especially indirect gasification in a dual fluidised bed system where the energy needed for gasification is provided by the circulating material from a high temperature secondary reactor. When the circulating material is a CO2 sorbent, a sorption enhanced gasification (SEG) system results where the circulating solid, in addition to the energy provided by sensible heat, supplies additional heat by means of the exothermic carbonation reaction with the CO2 generated from biomass gasification. In the presented work, the SEG process was studied for a biogenic waste material (consisting of the organic fraction of municipal solid waste) in a 30 kWth bubbling fluidised bed reactor using lime as CO2 sorbent. The effect of the main operating variables (temperature, steam-to-carbon (S/C) ratio and sorbent-to-biomass ratio (Ca/C)) on gas quality was assessed. M-modules (M=(H2-CO2)/(CO+CO2)) between 1.2 to almost 4 have been obtained acting on the variables that mostly affect the permanent gas composition, i.e. gasification temperature and/or sorbent-to-biomass ratio. ; This work has been carried out as part of the European Commission Horizon 2020 Framework Programme project FLEDGED (Grant agreement No. 727600) and the project WASYNG (No. RTI2018-095575-B-100) funded by the Spanish Ministry of Science, Innovation and Universities. Authors thank also the Regional Aragon Government (DGA) for the economic support under the research group's programme. ; Peer reviewed

14 slides.-- Presentation showed at the Final Workshop FLEDGED Project: flexible Sorption Enhanced processes for biomass to DME conversion, 27-28-29 October 2020. ; Assess the performance of the Sorption Enhanced Gasification process in a 30 kWth bubbling fluidized bed reactor (BFB) placed at the Instituto de Carboquímica (CSIC) (Zaragoza, Spain). ; This project has received funding from the European Union's Horizon 2020 research and innovation Programme under grant agreement No. 727600. ; Peer reviewed

8 figures, 5 tables ; Sorption-enhanced gasification (SEG) is a promising indirect gasification route for the production of synthetic fuels since it allows the H2, CO and CO2 content of the resulting syngas to be adjusted. This SEG process has been successfully demonstrated at pilot scale for lignocellulosic biomass and other agricultural and forest waste products, mainly focusing on H2-rich gas production. Within this work, the potential application of the SEG process to a material derived from municipal solid waste (MSW) as feedstock is experimentally demonstrated in a 30 kWth bubbling fluidised-bed (BFB) gasifier. The influence of the sorbent-to-biomass ratio, steam excess and gasification temperature has been carefully analysed in order to understand their effect on SEG performance. Moreover, main conditions able to affect the resulting syngas composition, specifically in terms of H2, CO and CO2 content, have been indicated. Gasification temperature turned out to be the variable that most influenced syngas composition due to the limiting mechanisms associated with the carbonation of the CaO used as bed material. This operating variable also determined biomass conversion, together with solids residence time in the gasifier, resulting in a wide variation of fixed carbon conversion under the studied conditions. Finally, tar yield and composition were evaluated as a function of temperature and the sorbent-to-biomass ratio used, resulting in tar contents as low as 7 g/Nm3 (dry gas), consisting mainly of 1-ring aromatic compounds. ; This work has been supported by the European Commission (FLEDGED project, grant agreement No. 727600); the Spanish Ministry of Science and Innovation, the State Research Agency and the European Founds for Regional Development (No. RTI2018-095575-B-I00, MCI/AEI/FEDER, UE); and the Regional Aragon Government (DGA). ; Peer reviewed

6 Figuras.- 1 Tabla ; [EN] Synthetic fuel production from renewable energy sources like biomass is gaining importance driven by the ambitious targets for reducing greenhouse gas emissions worldwide. Sorption enhanced gasification (SEG) proposes carrying out the gasification of biomass in the presence of a CO2sorbent, which allows producing a syngas with a suitable composition for a subsequent synthetic fuel production step. The Environmental Research Group of ICB-CSIC is involved in the assessment of this enhanced gasification process focused on residual biomass as a feedstock, analysing the influence of the main operating parameters (i.e. temperature, steam excess, residence time, .) in the different products obtained (gas, solids and tar). This work has been initiated in the framework of the EU H2020 Programme project FLEDGED [1] and it is going to be continued throughout the recently assigned WASYNG project, funded by the Spanish Ministry of Science, Innovation and Universities. In this work, some of the results obtained for one of the feedstocks studied are presented. ; [ES] La producción de biocombustibles sintéticos a partir de energías renovables como la biomasa constituye una de las principales soluciones para conseguir reducir de forma notable las emisiones de gases de efecto invernadero a nivel mundial. En concreto, la gasificación indirecta de biomasa con vapor en presencia de un sorbente de CO2 permite producir un gas de síntesis con la composición adecuada para un proceso posterior de síntesis de un biocombustible. El grupo de Investigaciones Medioambientales del ICB-CSIC se encuentra investigando este proceso de gasificación aplicado a biomasas de origen residual, estudiando la influencia de las principales variables de operación (tales como la temperatura, exceso de vapor, tiempo de residencia.) en los principales productos del proceso (gas, sólidos y alquitranes). Esta investigación ha comenzado en el marco del proyecto Europeo FLEDGED del programa H2020 [1] y continuará en el marco del recién asignado proyecto WASYING, financiado por el Ministerio de Ciencia, Innovación y Universidades. En este trabajo se muestran algunos de los resultados obtenidos para una de las biomasas analizadas hasta el momento. ; This work has been carried out as part of the European Commission Horizon 2020 Framework Programme project FLEDGED (Grant agreement No. 727600) and the project WASYNG (No. RTI2018-095575-B-I00) funded by the Spanish Ministry of Science, Innovation and Universities. Authors thank also the Regional Aragon Government (DGA) for the economic support under the research groups' support program. ; Peer reviewed

The operational limits of a commercial nickel-based catalyst under the conditions of a sorption-enhanced steam-methane reforming process coupled to a Ca/Cu chemical loop are investigated for high-purity H2 production in a cyclic operation. The performance of the reforming catalyst is tested by means of a high number of oxidation-reduction-reforming cycles. After 100 oxidation-reduction cycles, this catalyst retains its exceptional reforming activity. The methane conversion values are close to the thermodynamic equilibrium under very demanding conditions: temperature between 500 ºC - 700 ºC and mass hourly space velocity of 8.8 kgCH4 h-1 kgcat-1. After 200 cycles, the sample shows reduction in its reforming activity in line with a lower dispersion of the Ni species. Sintering of Ni nanocrystals is evidenced during the oxidation-reduction multi-cycles. The performance of the catalyst after 200 oxidation-reduction cycles mixed with a CaO-based CO2 sorbent is studied under optimal conditions calculated for the sorption-enhanced reforming process coupled to a Ca/Cu cycle (temperature of 650 ºC, steam/methane ratio of 4, sorbent/catalyst ratio of 4 and space velocity of 0.75 kgCH4 h-1 kgcat-1). Remarkably, an equilibrium value over 92 vol.% H2 concentration is achieved, highlighting this catalyst as a promising candidate for the next steps of the process development. ; The authors acknowledge support received from the European Union Seventh Framework Programme FP7 under grant agreement No. 608512 (ASCENT Project) and the Regional Government of Aragon (DGA) under the research groups support programme. The authors wish to thank J.M. Pardo for participating in the experimental work. ; Peer reviewed

Abstract of the talk delivered at the 29th European Biomass Conference and Exhibition, EUBCE 2021, Virtual, Online, 26 April 2021 - 29 April 2021, 261619. ; In this work, a sorption-enhanced gasification (SEG) process is studied using the organic fraction of a Municipal Solid Waste (MSW) as feedstock in a 30 kWth bubbling fluidised bed (BFB) reactor. Experiments using steam-to-carbon ratios in the range of 1 to 1.5 molH2O/molC with different sorbent-to-biomass proportions and gasification temperatures were conducted in a 30 kWth bubbling fluidized bed reactor. Solid residence time in the reactor was modified through the biomass and CO2 sorbent flow rates fed to the reactor. The influence of each operating variable in the syngas composition as well as in the yield and composition of the tar produced has been determined through these experiments. Moreover, it has been calculated char conversion in the gasifier for the different experiments performed with the objective of elucidating a semi empirical model for predicting such conversion as a function of the gasification temperature and solid residence time in the reactor. ; The effect of main operational conditions for the Sorption Enhanced Gasification procees (SEG) on gas quality and tars has been evaluated in a 30 kW bubbling fluidized bed reactor using the organic fraction of municipal solid waste (MSW) as feedstock. The process has been proved to be flexible, and gasification temperature appears to be the variable that mostly affected the M-module in the syn-gas produced and also the presence of light hydrocarbons and tar yield. The steam-to-biomass (S/C) ratio does not influence the permanent gas composition (i.e. the M-module), but affects the content of light hydrocarbons in the syngas as well as tar yield. The sorbent-to- biomass (CaO/C) ratio influences mainly the C3-C4 hydrocarbons content and the tar yield (due to the catalytic effect of CaO towards tar cracking). ; This work has been supported by the European Commission (FLEDGED project, grant agreement No. 727600); the Spanish Ministry of Science and Innovation, the State Research Agency and the European Founds for Regional Development (No. RTI2018-095575-B-I00, MCI/AEI/FEDER, UE); and the Regional Aragon Government (DGA). ; Peer reviewed

10 Figures, 6 Tables.-- © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ ; The combined performance of a synthetic CaO-Ca12Al14O33 sorbent and an Ni-MgAl2O4 reforming catalyst was tested in a fluidized bed reactor under relevant operating conditions for the sorption-enhanced reforming (SER) process. The effect of CH4 space velocity (i.e. kgCH4/h·kgcat), steam-to-carbon (S/C) ratio and superficial gas velocity on product gas composition was assessed, as well as the effect of regeneration conditions on material performance. Moreover, a bi-functional material prepared by mechanical mixing of the separate materials was also tested in the reactor under consecutive SER/regeneration cycles. H2 contents as high as 96 vol% (N2 free, dry basis) were achieved under SER operation, using the separate materials working with an Ni content of 3.75 wt% in the solid bed at 650 °C with S/C ratios of 3 and 4. This solid system is able to process up to 0.63 kgCH4/h·kgcat at 0.1 m/s superficial gas velocity and with an S/C ratio of 4, although the CH4 input has to be reduced to 0.33 kgCH4/h·kgcat when working with a lower S/C ratio. Similar H2 contents to those found with the separate materials were obtained with the combined sorbent-catalyst material working with 0.33 kgCH4/h·kgcat at 0.1 m/s superficial gas velocity and S/C ratios of 3 and 4. The CO2 sorption capacity of the combined material produced the same as that of the separate sorbent particles (i.e. around 0.25 gCO2/g calcined sorbent), while remaining stable throughout the SER/regeneration cycles. ; This work was supported by the European Union (Grant agreement No. 608512) and the Regional Government of Aragon (DGA) under its research groups support programme. ; Peer reviewed

The joint performance of a CaO-based sorbent and a Ni-based commercial catalyst has been assessed under relevant conditions for the SER stage in the Ca/Cu H 2 production process. These conditions comprise processing CH 4 space velocities suitable for the scaling up of the process, operation of the sys- tem at pressure, and testing materials that had experienced up to 200 oxidation/reduction cycles. The system, catalyst and CaO-based sorbent, was able to fulfil the SER equilibrium composition up to 2.5 kg CH 4 h 1 kg cat 1 ,CH 4 space velocity that would allow the scaling up of the process. In this way, a gas stream containing up to 95% vol. H 2 was obtained at 923 K, steam to carbon ratios of 3.2 and 4, sor- bent to catalyst weight ratios from 4 to 15 and for operation pressures between 1 and 9 bar. The effect of oxidation/reduction cycles on catalyst performance was assessed, and the mixture sorbent and aged cat- alyst was able to process up to 2.5 kg CH 4 h 1 kg cat 1 , corroborating the operational limit determined for the fresh materials. The total operation pressure (from 1 to 9 bar) did not have an important influence on H 2 yield, and/or materials performance. Sorbent carbonation reaction rates up to 4.42 * 10 2 kmol h 1 kg sorb 1 were determined in the experiments, being this parameter responsible of the limit in CH 4 space velocity that can be successfully converted through this sorbent/catalyst system. The experimental results have been successfully described by a pseudo-homogeneous reactor model that incorporates the main kinetic expressions of the reactions involved in the SER stage. ; This work acknowledges the support by European Union Seventh Frame Programme FP7 under grant agreement n° 608512 (ASCENT Project). Laura Díez acknowledges the FPI fellowship (ENE 2012-37936-CO2-01, BES-2013-064616 financed by MICINN). The authors want also to thank the support from the Regional Aragon Government (DGA) under the research groups support program ; Peer reviewed